1. Field of the Invention
The present invention relates to novel catalysts and to the utilization thereof for the oxidation of sulfur containing compounds, and, more especially, to such novel catalysts and the utilization thereof for the oxidation of carbon disulfide and/or carbon oxysulfide and/or mercaptans to sulfur dioxide, or for the simultaneous oxidation of hydrogen sulfide together with such sulfur containing organic compounds to SO.sub.2.
2. Description of the Prior Art
It is known to this art that certain industrial effluents, and in particular those effluents emanating from Claus units, contain sulfur and/or oxidizable, polluting sulfur containing compounds, which species must be treated such as to be converted to sulfur dioxide by oxidation. The notable sulfur compound pollutants present in these effluents are mainly hydrogen sulfide and sulfur containing organic compounds, such as carbon disulfide and/or carbon oxysulfide and/or mercaptans. Indeed, hydrogen sulfide is a product of hydrolysis of such latter compounds.
It too is known to treat effluents containing hydrogen sulfide by burning or incinerating same at high temperatures, but this method is now obsolete, both because of the high energy consumption which it entails and, from a technical point of view, because cf the amount of oxygen which it requires.
Furthermore, catalytic processes for treating gases containing hydrogen sulfide have already been proposed; however, these processes characteristically exhibit the disadvantages of insufficient catalytic activity, of not effecting complete oxidation of the hydrogen sulfide at a sufficiently low temperature, and of having an insufficiently long catalyst life.
It is also known, from published French Pat. Application No. 2,144,148, to oxidize those sulfur compounds contained in sulfur dioxide gas by catalytic transformation at 400.degree.-600.degree. C. in the presence of a catalyst containing an active phase comprising a mixed oxide of the spinel type of the general formula M.sub.1x Cr.sub.Z Fe.sub.2-z O.sub.u in which M=Zn, Cu, Co, Ni, Mg, Mn or Cd. Such a catalyst, apart from its unsatisfactory performance, presents the considerable inconvenience of requiring for its preparation a calcination at a temperature of at least 650.degree. C. for 4 hours in order to give rise to the spinel structure.